P‐186: Preparation of Photosensitive Cholesteric Liquid Crystals

In this study, photo‐responsive cholesteric liquid crystals (CLCs) were prepared by blending E7 with a photo‐responsive chiral radical, CHAD‐3C‐S. Subsequently, the UV triggered tunable photonic band gap of the prepared CLCs was investigated using a polarized optical microscope (POM) and a spectrometer. It was found that a tunable reflection color within the visible range was produced in response to UV irradiation, accompanied by a red shift of the reflection signal in the spectra. Moreover, the time required to tune the reflection signal located at 660 nm from 410 nm has been determined to be a mere 49 s, a significant reduction in comparison to other literature reports. These findings provide compelling evidence that CHAD‐3C‐S exerts a regulatory influence on the photonic band gap (PBG) of CLCs, and that the basic modulation approach has been successfully established.